Pink Snow Mould

The Issue

Causal Agent: Microdochium Nivale

Hosts: All turfgrasses in Canada

Epidemiology: Pink Snow Mould is the name given to the phase of the Mircodochium nivale pathogen which develops under snow cover. The pathogen, which can infect a plant in as little as 30 days of snow cover, is active from 0°C to 16C°.

Target: Foliage

Evidence: Radial growth of mycelium, under snow cover, from initial infection sites results in the distinct round patches (up to 12 inches in diameter) which may be covered with fluffy white mycelium. As the snow melts, patches appear bleached white to tan, sometimes with a pink margin.

Clues:  Sunlight can induce the production of pink mycelium which results in the classic ringlink patch with a pink outer margin. A distinguishing characteristic of Pink Snow Mould when compared to the Grey Snow Moulds is that it does not produce sclerotia.